Leo's Oath
by ducky76
Summary: Leo has given Karai many chances to be honorable, but when one of his brothers falls by her sword, her chances are over. Leonardo swears revenge and his family sees him transform into a grim shadow of his former self.
1. The Oath

Raphael felt groggy as he began to wake up. His entire body was so tired that it felt almost numb, but that was the least of his worries. Somewhere nearby (or was it far? He couldn't tell because the volume of the voices seemed to drift in and out) familiar voices were speaking. One was so soft and gentle, the other seemingly trying to sound collected and in control.

"Any change?"

"Neither of them has woken up yet. Are we sure that they all left."

"There doesn't seem to be any of them left. April's on her way, so hopefully she'll get here before anyone decides to come back."

"They won't come back if they're counting this as a victory…"

"What do you mean by that?"

"Leo, he's a mess and they know it. I'm afraid that he's in too bad of shape to be moved. His spinal cord was completely severed."

"Does that mean he'll be paralyzed?"

"If he's lucky… But I don't… I don't think he'll make it."

"Are you sure? I mean… He's too strong to… He can't."

"Yes, I'm sure! I wish I wasn't. But… God, he's bled so much and he's in such bad shape. There's only so much I could do and this… There's no way I could help him. He's… he's gonna die, Leo." A sob was choked back by the voice in question.

Raphael's grogginess started to dissipate the second he realized that his younger brother had said that word die. Coming to himself, he realized that he was actually lying on his side on the cement roof of a building with his left cheek pressed against the ground. It was nighttime. Confused by where he was, he focused on his brothers' conversation. Leonardo and Donatello sounded grave and distraught. Who were they talking about? _Think Raphael. Think._ What had he done last? They'd been in the lair. Pizza. Then patrolling with Michelangelo. But what happened?

Karai! She'd shown up. Ambush. There'd been so many Foot ninja, too many for just two turtles to handle, and Michelangelo… "Mikey!" He'd been hurt! Raphael had heard his youngest brother's yell and had turned away from his fight with Karai to see Michelangelo fall to the ground. He broke ignored Karai and went on to attack the ninja nearest his brother. After that he couldn't remember much more… Did he hit his head? That didn't matter. What his brother's had said… Was Michelangelo dying?

Raphael suddenly became aware that Leonardo was beside him, looking at him worriedly. He tried to push himself up but his tired arms wouldn't let him. And instead of helping, Leonardo just set a hand on his arm, gently holding him in place.

"Where'd she go, Leo? I'm gonna kill her!" Raphael tried his best to sound strong while he put up a weak struggle against his brother's hold.

"Karai got away." Donatello was looking at Raphael fearfully from over the leader's shoulder. He too was kneeling on the ground, only beside another of the brothers. He looked like he was trying to hide something.

"Mikey!" Raphael called stubbornly, looking at the motionless turtle. He again fought against Leonardo's hold, but even in anger he was too tired.

"Raphael! You need to stop moving around like that! You're hurt!" Leonardo didn't have to put up much effort, though. He held him down firmly with one hand and rubbed against his plastron in a soothing gesture with the other.

"But Mikey! I want-"

"He's unconscious, Raph," Leonardo said softly.

"Michelangelo!" Raphael called out. When he once again received no reply, he stopped fighting. "Fuck! What's wrong with Mikey?"

"He'll be fine." Leonardo relaxed a bit at seeing his brother stop.

"He's hurt… I let 'im get hurt Leo!"

"Raph, stop it or you are going to hurt yourself worse!"

"It's my fault… all my fault."

"He's going to be okay," Donatello said, but Raphael heard his hesitance and felt again that he was hiding something.

Raphael looked Leonardo in the eyes. "I failed 'im."

"You didn't fail anyone," Leonardo said.

"I let my guard down… I didn't have his back enough. I'm sorry… so sorry."

"You did great, Raph. Mike will be fine." Leonardo's eyes were filled with tears, and Raphael could hear the strain in his voice. "You saved his life."

"But he's-"

"Going to be okay," Leonardo insisted. "He'll just have a nasty headache and some stitches to deal with. Michelangelo will be fine."

"But Leo…" Raphael felt worn out, no energy left to fight back his tears. "I heard Donny. Mikey's gonna… he's gonna…" Why did his head feel so fuzzy?

"You misheard."

"'M sorry," Raphael slurred. If he'd been a bit more alert, he might've heard the groan from his youngest brother.

"Shhhh." Leonardo set his hand on the back of Raphael's neck, and Raphael thought the warmth felt amazing.

"I heard 'im… heard ya both… he's dyin'…"

Leonardo shook his head and suddenly let his tears fall. "Not Mikey."

"Wish I coulda… done a… better job…"

"You did a perfect job," Leonardo whispered. "You always did a perfect job."

"Raph?"

Raphael looked past Leonardo to see Michelangelo staring at him in horror. He saw Donatello pulling him to the side and whispering something.

"See?" Leonardo said. "He's fine. He's going to be just fine."

Raphael looked away from the two younger turtles to his leader. "Then… who?"

Leonardo let out a sob almost simultaneously with Michelangelo's cry of shock. "Oh, Raph," he said, his head hanging a bit.

"Leo?" Looking around at all three of his brothers, he noticed that they were all giving him the same pitiful look. "Leo, what's… wrong?"

He faintly heard Donatello's cry to not move him as Leonardo pulled him up a bit so that his shell rested against the eldest turtle's plastron. One strong arm held him tight around the chest, while the other rubbed his arm. Leonardo rested his cheek against the top of Raphael's head. "It's going to be okay, Raph," he whispered fearfully. "Shhhh."

"Leo…" Raphael felt confused, but he was too tired to keep asking questions.

"I love you, Raph," Leonardo choked out. "I don't say it enough. Spent too much time fighting with you. But… God… I only did it because I wanted to protect you. I wanted to keep you safe. That's my job… I just… I just want you to be okay. You're my brother, and I love you so much."

Now he was really confused. Why on earth would Leonardo be getting all sentimental suddenly? Normally, he might've blown him off, but something about the urgency in his voice made him feel like he should respond. "You too, bro…" His eyes felt heavy. "So tired…"

"No! Don't go." Michelangelo knelt nervously beside him.

"Ain't goin'… anywhere…" Raphael mumbled. "Just… nap…"

"Raphael…" Donatello grabbed one of his hands.

"Donny?"

Donatello shook his head to keep back tears. He put on a fake smile as one of his hands pressed against Raphael's side. Raphael wondered briefly why, but it didn't matter that much. "You were great, tonight. You took care of Mike."

"Woulda done it… for you, too…" Raphael glanced at Michelangelo. "Glad yer… alright.

Leonardo could've sworn his own heart stopped the second he felt Raphael go still in his arms. He shook him very lightly. "Raphael?"

Donatello let go of Raphael, his one hand covered in his brother's blood. "He's… gone."

Leonardo shifted his brother's body in his arms so that he could see his face. His eyes were still open, their glassy appearance eerie. The eldest turtle let out one final sob as he closed Raphael's eyes.

Michelangelo shot to his feet, ignoring the dizziness from his concussion and the blood flowing from the wound in his shoulder. He paced back and forth for a minutes, breathing erratically. "No no no no no no no…" He stumbled a bit and looked down to see that he had tripped over. Raphael's sai was covered in blood. He knelt down and picked it up.

"Mike?" Don's soft voice called.

"Fix it, Leo," Michelangelo whispered. He wiped at his eyes with the back of his hand.

They were all silent for a moment, before Michelangelo slammed the sai into the ground. "How did this happen!" he shouted.

He made to stand but did so too quickly. Fortunately, Donatello was there for support when he felt a bit faint. The scientific turtle was about to say something when his shell cell began to ring and he could hear the sound of April's van on the street below. "Leo, I'll… uh… get Michelangelo down to the van." He began to walk away with Michelangelo, but stopped to look back at the other two. Leonardo had not made a move to get up. "Do you want me to send Casey up?"

"No. I'll bring him down in a minute."

Donatello nodded unsurely but proceeded to leave with his exhausted, dizzy little brother.

Once the two of them were gone, Leonardo held Raphael tight to him a moment longer. "I'm sorry," he whispered. "I'm so sorry, Raphael. It shouldn't have been you. Not any of you. I should have taken care of her a long time ago, but I kept giving her chances. I made a mistake that none of my brothers should have paid for. Never again. Karai may have gotten away tonight, but I will not let her get away with this. She will pay this time. I swear."


	2. Sleepless Nights

Donatello found that his mind wasn't at all focused on any of his projects that night. His mind had hardly been focused in the two weeks since Raphael had been killed by Karai's sword. He often caught himself staring at his computer screen wondering what he was doing in front of it. A look at the clock always confirmed the great length of time he'd spent sitting there, doing nothing at all.

He wasn't the only member of the family who was unable to go on with his daily routine. Michelangelo hadn't touched a single video game or even the television remote once. When they'd first brought him home, he'd been antisocial and uncharacteristically quiet. Four nights after the fight, he'd taken all of Raphael's alcohol from the fridge and drank all of it. Everyone, except for an MIA Leonardo, had seen just how unpleasant and angry, drunken Michelangelo could be that night. He'd cursed out his family and thrown a bunch of Raphael's belongings onto the floor. Since that night, Splinter was working with him on meditation methods daily. Of course, it hadn't changed him back to the easy-going turtle that he usually was. When he wasn't just half-heartedly skateboarding around the sewers at the suggestion of Splinter, he could often be found staring angrily at the Nightwatcher helmet on his father's shelf.

Leonardo was just as bad. He either spent his time in the dojo or out on patrol. He hardly spoke a word to anyone when he came home in the mornings. He didn't even try to console his brothers, and he usually would've been the first to jump to their aid. Living in the house with Leonardo was like living with a ghost. He was rarely ever seen, and the faint sounds of Raphael's punching bag being put to use behind the closed doors of the dojo was almost haunting to the rest of them.

Donatello knew that Splinter often entered Raphael's bedroom and cried at the sight of all of his belongings, all set back into place after the scene caused by his youngest son. April and Casey had been around more often than usual, constantly offering to get anything the mutant family needed. April brought food every day, more food than they needed, and she spent a lot of time with Splinter, trying to cheer him up. It was a hard task when she hardly felt cheerful. Of course, Casey seemed just as lost as any of them without Raphael. The guy hardly knew any human beings on a personal level, and Raphael had been his best friend.

All things considered, Donatello knew that he was probably doing the best of all his family members, even if only for the sake of being strong for the rest of them. With a yawn, he decided to get to sleep in hopes that sleep might clear his mind. After brushing his teeth and turning off all the lights, he collapsed into his bed. Unfortunately, every time he tried to sleep he saw Raphael, his eyes lifeless and empty as he lay in Leonardo's arms.

"Don, are you awake?"

He was half asleep when he heard the voice, and his breath hitched as he looked to see a dark shadow of a form standing in his doorway, the light from behind making him the visitor impossible to make out. Before, it had always been Raphael standing in that doorway late at night. He would come there just as Donatello was getting ready to go to bed, asking if he wanted to work on the Battle Shell of the Shell Cycle. Donatello knew that was code for 'I'm upset and need you to get me to talk to you,' so he'd always agreed to stay up even later, despite his exhaustion, to wait until his brother was ready to open up. Sometimes it took all night. Other times it didn't take very long at all. And still, some nights Raphael never said a word, but Donatello understood. He knew that those nights were the ones when Raphael was most distressed, but he also knew that the mere fact that he understood Raphael's distress and need to be in company without pushing him was enough to help calm his brother.

This night, when he heard the voice and saw the figure in his doorway, Donatello half-expected Raphael to be there.

The figure shifted uncomfortably from one foot to the other. "Sorry, go back to sleep." He turned to walk away.

"Wait, Leo." Donatello sat up and watched his brother turn back. "I wasn't sleep yet. Turn the light on."

Leonardo did as he was told. Donatello rubbed at his eyes and blinked a bit until they adjusted. When he got a good look at his brother still standing in the doorway, he saw just how tired and sickly he looked. Leonardo's shoulders were slightly slouched and his skin had an unhealthy pallor to it. "You sure I didn't wake you?"

"You didn't." Donatello swung his legs over to the side of his bed. "You haven't been sleeping at all, have you?"

Leonardo didn't reply to the question.

Donatello sighed. "What do you need?"

"I wanted to ask for your help with something." Leonardo finally entered the room and walked towards Donatello's computer desk. "Do you have a map of the city that you could pull up?"

"Sure." He walked over and sat in his desk chair. He typed in his password and looked back at his brother. "What's this about?"

"I want to plot out these locations on it." Leonardo set down a sheet of paper on the table. On it was a list of different street names.

"Okay," Donatello replied, slightly confused. He began to do as his brother requested. "What are all of these?"

"Foot."

Donatello paused and looked at his brother. "The Foot? Leo, where did you get all of these?"

"It's a list of places that I've run into Foot ninja on my patrols in the past two weeks."

"In the past two weeks? There are nearly thirty locations listed here. You haven't been fighting them all?"

"I have." Leonardo looked very dark as his looked his brother directly in the eye. "They aren't getting away with their crimes anymore, Don."

"There's no way that you could possibly have just run across this many Foot ninja on your patrols." Donatello completely stopped adding in the locations. "You've been out there looking for them specifically." He only had to hear his brother's silence to know that it was the truth. "And no sign of her, I'll bet."

The look on Leonardo's face darkened even more than before.

"You've been looking for the Foot every night since we lost Raph hoping to run into Karai," Donatello accused.

"And I want you to plot those locations on that map so that we can try to find their headquarters."

"I can't help you with that." Donatello got out of his seat.

"I'll plot it myself," Leonardo said, taking his brother's place. "I'll just need you to take a look after I'm done to tell me any likely locations where Karai could be hiding."

"You aren't thinking straight." Donatello set a hand on his brother's shoulder. "You've only been practicing and patrolling lately. Have you gotten any sleep at all?"

"An hour or two here and there."

"That isn't enough for anyone. You're not in a fit state to be out there looking for revenge, Leo. You need to get sleep."

"I can rest when Karai is gone," Leonardo snapped.

Donatello looked at his brother with pleading eyes. "Raph wouldn't want this."

"He would be doing the same thing if it had been any of us."

Donatello sighed and grabbed his brother's hand from the computer's mouse. "He wouldn't want to see you turned into this."

Leonardo ripped his hand out of his grasp. "I let this slide for far too long, Donatello. If I had just gotten rid of Karai before, he wouldn't be gone. It's my fault that he's dead. I'm not giving her the chance to do it again to any of my other family members. And she will pay for what she did to Raphael, whether I have your help or not."

Donatello watched him silently for a moment before giving him a nudge. "Give me my seat back. I'll help you on two conditions."

Leonardo stood. "What're they?"

"First of all, you get some sleep."

Leonardo nodded. "I'll try."

"And when we find her, you don't go in there by yourself, Leo." Donatello gave him a very serious look. "I mean it. Mike, Casey, and I will go with you. And Master Splinter has to give the okay. We aren't doing this behind anyone's back and we aren't doing it until everyone is in the right state."

"I'll agree to that as long as no one tries to hold me back," Leonardo said.

Donatello knew that it was the best he would get out of his brother that night, so he went back to plotting the points on the map. "Get to bed Leo. And sleep in tomorrow. You look terrible."

Leonardo grunted in response, much like Raphael used to do, and made his way out of the room. Despite having chastised his brother for the drastic methods of finding Karai, Donatello couldn't blame him for his drive for revenge. He found that this night, for the first time in a while, he was completely focused on his project.


	3. Laying the Blame

Leonardo made his way out of the out of Donatello's room, fully intending on getting to his own, but his plans changed when he noticed a dark figure standing in the shadows by the kitchen. He drew his katanas and jumped into a defensive fighting stance.

"Someone's jumpy," Michelangelo said as he stepped into better lighting. His arms were crossed over his chest, and Leonardo could not see his eyes as they were shadowed by the way he tilted his head.

"What are you doing up so late, Mike?" Leonardo asked.

"Could ask you the same thing." Michelangelo flipped on the light switch and walked into the kitchen. He reached into the cabinet for a glass. "You just get in?"

"I was talking to Donnie."

Michelangelo poured himself some water. "What about before you woke 'im up?" He took a sip. "Out lookin' for a fight?"

The older turtle frowned as he turned away. "I'm going to bed."

"So you'll look for a fight out there every night," Michelangelo called after him, "but you're gonna avoid one here, huh?"

Leonardo turned around and gave his brother a hard look. "Are _you_ looking for one?"

"I didn't say that."

"It sounded like you were implying it, Mike."

The two stared at each other silently for a moment, before Michelangelo put the glass in the sink. "Why do you keep going out alone?" He looked back at his brother. "Do you think you're gonna fix it?"

"It's none of your business."

"Or are you tryin' to get killed, too?"

Leonardo rolled his eyes and sighed. "Go back to bed."

"No." Michelangelo walked closer to him. "You know, Raph couldn't take 'em all. If he couldn't, you can't either dude."

"You're the one who can't take them. Did you forget that Don and I ended that fight while you were out cold?"

Michelangelo's eyes darkened and his body went very still, tense. His brother realized a moment too late that it was only the brief calm before the storm, as Michelangelo growled and slammed him into the wall. With his hand gripping Leonardo's throat, he pulled him back and slammed his shell against it another time, holding him there. "So you think it should've been me instead of Raph? It's my fault he's dead, huh? Is that what you think?"

Leonardo didn't fight his brother, but he narrowed his eyes at him. "No," he said his voice raspy and quiet. "That's what you think."

"You know what? This is your fault! Do you know how many times you just let Karai go? Raph would still be alive if you woulda let us get rid of her. You killed him!"

"I know," he rasped so softly it couldn't be heard.

"What did you say?" Michelangelo loosened his grip a bit.

"I know. It is my fault."

The smaller turtle growled again and tightened his grip before letting go entirely. He punched his fist into the wall beside his brother's head.

"I see those anger management sessions with Sensei aren't helping out much."

Michelangelo snarled and looked as if he might slam him into the wall a second time. Instead, he simply stormed off to his bedroom and slammed the door, leaving his weary brother behind. Leonardo looked over to the light coming from Splinter's open door and realized that his father had witnessed the encounter. "Sorry Sensei."

"I will speak with him in the morning," the rat said.

"No need. It's over and done with. He's just blowing off steam."

"I will still speak with him in the morning," Splinter said firmly. "Tonight I will speak with you, though."

"I was actually about to get to bed-"

"Leonardo."

The turtle sighed and followed his father into the room, kneeling in front of him. Splinter sat cross-legged. "Your brother may be 'just blowing off steam,' but he seems to be blowing it in the wrong direction."

"Tell me about it-"

"As are you, my son. I have tried to ignore the way that you have handled the loss of Raphael. You have always been the steadiest and most stable of your brothers, Leonardo, so I believed that any negative ways of expressing your grief would pass quickly. I was wrong."

"I mean no disrespect, Sensei, but I'm handling everything fine. You have enough to worry about with Michelangelo."

Splinter gave him a thoughtful look. "Tell me… What do you believe is the source of your brother's problems?"

"Guilt," Leonardo said. "He thinks it's his fault because Raphael turned his back to Karai when he was trying to protect him."

"He does not say it," Splinter said, "but it is true. He has tried many times to put those words into my mouth and into Donatello's. I believe he wants us to punish him as he is punishing himself."

"That's stupid. He'll never learn to cope that way."

"If it is so stupid, why do I fear that another of my sons is having similar feelings?" He gave Leonardo a knowing look. "I know that you, too, are blaming yourself for your brother's passing."

Leonardo looked down at the floor. "Maybe I don't care to cope."

"And will I then have lost two sons?" Splinter's tone was harsh and scolding, forcing Leonardo to look back up at him. "I am afraid for you most of all my sons. Donatello may be depressed and Michelangelo may be coping poorly, but you, Leonardo, are destroying yourself day after day and night after night."

"Father, I…"

"I know it is easy to be consumed by guilt, but-"

"Do you know how many times Raph told me that I should get rid of Karai?" Leonardo cried. "He knew that she had no honor. I think I even knew it. But I still let her go, over and over again. I thought that she could change."

"And Raphael loved you for that. He didn't have it in him to forgive and to hope the way that you do, and, though he fought you over these issues, he loved you for your ability to see the light where he could not."

Leonardo's eyes watered a bit. "Did Raphael ever actually say that?"

"Not in so many words, but a father knows his sons. You were Raphael's brother. Do you think that in his final moments he could've been angry with you for having wished to change a person that you thought you saw hope in? You were Raphael's brother and he loved you."

"And I failed him."

"Raphael knew the risks of turning his back to Karai in that battle, my son. Even the greatest ninja will turn his back to an enemy in battle when he must. You had to turn your back on Karai to protect your own honor and your family's honor, just as Raphael did to protect his brother's life. No one is at fault except for the dishonorable enemy who takes advantage of the exposed back before him."

Leonardo wiped at the tears on his cheeks with the back of his hand. "She will be punished for what she's done." He gave his father a determined look. "I respect you, Father, but if you try to stop me from doing what I must do, then I will not listen."

"Then I will not try to stop you," Splinter said wearily. "Just know that a desperate man alone cannot win the fight to save his own soul. He must recognize the help and guidance of those who care for him." He set his paw on his son's closed fist. "Please do not lose yourself in this fight. Our family could not handle such a loss."

Leonardo looked back at the ground. "If we're done, I promised Donatello that I would get some sleep."

Splinter sighed and removed his hand. "Yes, of course."

Leonardo slightly bowed to his father before getting to his feet.

"As much as you and your brother fought…"

Leonardo stopped at the doorway but did not look back at his father.

"As much as you fought, you are more alike than either of you could have ever known."

Without a word, Leonardo left for his own bedroom. Once there, he collapsed onto his bed, willing sleep to take him.


End file.
